Broaching machine



J. L.. @Emme ET AL 27mm BROAGHING MACHINE lm m ma,

Filed Jan. 2l, 1928 14 Sheets-Sheet l dll es@ 'm6-54 7 I N VEN TOR5 u y www@ Q @azmcM/,Myw

ATTORNEYS jam 14; w35- .1. PERKINS ET Al. 2,0273@ BROACHING MACHINE Filed Jan. 2l, 1928 14 Sheets-Sheet 2 Wea* Z |32 llo HOQ INI/ENTORS gaf/M @www 29 a l ATTORNEYJ j M i@ J. n.. PERKHNS ET AL BROACHING MACHINE' Filed Jan. 2l, 1928 14 Sheets-Sheet 3v nolo HOO. HOC,

IN VEN TOR l M@ MMM Jan. 14, 1936. J, L PERKgNS ET AL, 2,027y4 BROACHING MACHINE Filed Jan. 2l, 1928 v 14 Sheets-Sheet 4 INVENTORS Q7. am@ PMMM @u Jan. 14, 1936.

J. L. PERKINS ET AL BROACHING MACHINE Filed Jan. 2l, 1928 14 Shveets-Sheet 5 NN oww INVENTORJ' Jan. 14, 1936. J. L. PERKINS ET A1. 2,027,401

BROACHING MACHINE Filed Jan. 2l, 1.923 14 Sheets-Sheet 6 mfa i? L\ gmntou @wim/@MCA m dumm* Jan- 14, 1936. J. 1 PERKINS Er Al. 2,027,401

BROACHING MACHINE Filed Jan. 2l, 1928 14 Sheets-Sheet 'T \O Si@ l T'lcfr' Z39 )(98 R k @ma loo 7 '69 v f 17o '7l -"l G. l0

70 hun :1I-IG ,4 58 V 53 un \\\1 m 59 INVENToRs 95a G54 ,37 2220, #7m/w A TTORNEY.

Jan- 14, 19,36 J. l.. PERKINS Er AL 2,027,401

BHOACHING MACHINE Filed Jan. 21, 1928 14 sheets-sheet 8 MLA..

BROCHING. MACHINE Filed'an. 2l, 1928 14 Sheets-Sheet 9 @an M, 1936. J, L, pERKlNS ET AL 2,027,40

BROACHING MACHINE Filed Jan. 2l, 1928 14 Sheets-Sheet l0 ATTORNEY.

3M-14,1936. 1 PERKINS ET A1. 2902784@ BROACHING MACHINE Filed Jan. 21, 192B 14 sheets-Sheet 11 A TTORNEY Jam.. i4, 1936. J. L. PERKINS ,ET AL. 2:27AM

BROACHING MACHINE Filed Jan. 2l, 1928 14 Shams-Sheet l2 E R rf; Werf' 29 T701 5 O INVENToR f Y o @gym/ MQ my A TTORNEY Jan. 14, 1936. J PERKWS ET AL 2,027,401

BROACHING MACHINE Filed Jan. 2l, 1923 14 Sheets-Sheet 15 Jan. 14, 1936. .1, 1 PERKINS 1- r AL l BROACHNG MACHINE Filed Jan. 21, 192s 14 sheets-sheet 14 INVENTORJ GMW www mw Irun l Jan. i4, 1936 BRAUHUING MACHINE Massachusetts Application .llanuary 2l, 1928, Serial No. Zidft llaims.

This invention is concerned with metal cutting machines and has for its general object the provision of a broaching machine adaptable to effecting the precision finishing of metal parts by open loroach cutting operations at a high rate of production.

Another object of our invention is the provision of a broaching machine incorporating mechanical features directed to the precision indexing of the metal cutting tools comprising the breaches.

A further object of our invention is to associate with a broaching machine, mechanisms for automatically effecting precision indexing of the Work or metal parts being cut whereby a plurality of precision cuts may be effected automatically upon the work.

A further object of our invention is to incorporate in a broaching machine of the character above referred to a mechanism for effecting the 20 precision indexing of the work about more than one axis.

A still further object of oui` invention is to eiect the automatic release of the Work from the .o after a predetermined number of operations upon rresented position of the work to the cutting tools the work has been effected by said tools.

A still further object of our invention is to coordinate in a broaching machine mechanisms which will effect the automatic presentation of the work to be cut by the broaching tools to the tool path. l

A still further object of our invention is to provide a broaching machine which will automatically engage or grip work to be cut by the broaching tools in precision relation to one prefinished surface thereof.

A still further object of our invention is to co'- ordinate in a broaching machine the foregoing referred to mechanisms in such manner that their 4i) functionings or cycles of operations will be controllecl in a predetermined manner relative to reciprocating cycles of operations of the broaching tools.

A still further object is to arrange the said coordinated mechanisms in such manner that extraordinarily heavy cuts by the broaching tools upon the Work blanks may be effected without the reactive stresses caused thereby interfering with the precision finishing of the surfaces being cut by the tools.

A still further object of our invention is the provision of an automatically operated broaching machine which is adaptable to the simultaneous cutting of a plurality of pieces of work.

Further objects of our invention will hereinafter become apparent from the following description of a broaching machine illustrated in the drawings to embody the various features of our invention. The essential characteristics thereof are summarized in the claims.

Our invention is concerned with improvements and further developments of the class of broaching machines known as open broaches that is, the cutting action is effected by the reciprocating movement of a series of cutting teeth which are caused to act upon the work, the work being interposed in the reciprocating path of movement of the cutting teeth. Such a machine is generally disclosed in our prior issued Patent No. 1,409,766 and, as in that patent, the present invention is illustrated as being embodied in a machine for eecting the cutting of gear teeth, but it will be understood by those skilled in the art that the machine to be hereinafter described in detail is adaptable to precision finishing or cutting of a variety of pieces of work heretofore ilnished or cut by milling operations.

In the present instance, we incorporate in the embodiment of our invention duplex mechanisms which may be alternately operated in coordina-= 14 t tion with a pair of mechanically attached or conconnected reciprocating slides supported on the machine frame in an upright, counterbalancedl relation, whereby the power required for reciprocating' the slides and the broaching tools supported and carried thereby is reduced to only that necessary to overcome frictional resistance in the operation of the slides and tools and the reactive resistances of the work when being cut by the tools carried by the slides. the productive capacity of such a mechanism, we provide on each of the slides two broaching tools, each tool comprising an oscillatable bar having mounted thereon a row or set of rough cutters and a row or set of finishing cutters, the rough cutters being eiective in doing the major cutting upon the work during reciprocation of the slide in one direction. The bars are oscillated on the completion of this roughing cut whereby the sets of finishing cutters carried thereby are brought into the cutting path, and a light nishing cut is effected over the previously effected rough cut, upon the return movement of the slide. An oscillatable broaching bar and attendant mechanism for its proper functioning is described and claimed in the Perkins, et al. Patent No. 1,486,604 issued March l1, 1924.

In vthe drawings, Fig. 1 is a plan View of a duplex broaching machine, embodying the features of our invention and for purposes of illus- To enhance tration is shown as being particularly adaptable to effecting the broaching of gear teeth and work blanks; Fig. 2 is an enlarged front elevation of one of the mechanisms incorporated in the machine for presenting work to the cutting path of the broaching tools of the machine, and for indexing the work relative to the tool path; Fig. 3 is a front elevational view of a work handling xture or mechanism which is a duplicate of the mechanism illustrated in Fig. 2; Fig. 4 is an enlarged fragmentary elevation of the work handling fixture or mechanism disclosed in Fig. 2; Fig. 5 is a fragmentary side elevation of the lower part of the mechanism illustrated in Fig. 2; Fig. 6 is a fragmentary side elevation of the mechanisms illustrated in Figs. 2 and 5, but with the mechanical elements thereof disposed in a diierent operative position than the positions of the same elements shown in Fig. 5; Fig. 7 is an enlarged cross sectional detail of a tool stroke control comprising part of the mechanism shown in Fig. 5 and taken along the line 'l--T of Fig. 5; Fig. 8 is a cross sectional detail of other parts of said mechanism and taken along the line 8 8 of Fig. 5; Fig. 9 is a cross sectional detail of a revolving support for work indexing mechanisms and taken along the line 9-9 of Fig. 4; Fig. 10 is a cross sectional detail of a precisioning plunger taken along the line Ill-l0 of Fig. 9; Fig. 11 is an enlarged side elevation of a. duplex work indexing head adapted to be removably mounted upon the revolving support shown in Fig. 9; Fig. 12 is a cross sectional assembly view of the duplex Work indexing head taken along a plane dened by the line I2-I2 of Fig. 11; Fig. 13 is a plan view, bottom side up, of a precisioning couple comprising one of the important elements of the work indexing mechanism illustrated in Figs. l1 and 12; Figs. 14 to 17 inclusive are detailed views of parts of elements comprising the Work indexing mechanism illustrated in cross section in Fig. 12; Fig. 18 is a fragmentary detail or side view of part of one of the broaching cutters; Fig. 19 is a cross sectional view taken through Fig. 12 along the line |9-I9 of Fig. 12; Figs. 20 to 25 inclusive are detailed illustrations of other parts comprising the duplex work indexing mechanism illustrated in Fig. 12; Fig. 26 is an enlarged cross sectional view taken longitudinally through the top portions of oscillatable bars or arbors which support broaching tools such as is illustrated in Fig. 18, this section being taken along either of the lines 26--26 of Fig. 1; Figs. 27 and 28 are two views of a precisioning means incorporated in the mechanism illustrated in Fig. 26; Figs. 29 and 30 are diagrammatic representations of the oscillated positions on the broaching tools; Figs. 31 to 37 inclusive are detailed illustrations of other elements incorporated in the mechanism illustrated in cross section in Fig. 26; Fig. 38 is an enlarged fragmentary side elevational view of one of the oscillatable bars or arbors for carrying the broaching tools; Fig. 39 is a cross section taken through one of the arbors or broach supporting bars along the line 39-39 of Fig. 38 and showing the manner of clamping the cutters thereto; Fig. 40 is a side elevation of a modied form of mechanism illustrated in Fig. 6 whereby the mechanism illustratedjn Fig. 6 may be operated automatically to cause the work indexing mechanism to present ynew Work to the cutting paths of the broaching tools; Fig. 41 is a cross sectional fragmentary View of the mechanism shown in Fig. 40, taken along the line 4|-,-4I of Fig. 4.0; Fig. 42

is a cross sectional detail of a revoluble indexing element incorporated in the mechanism illustrated in Figs. 40 and 41; Fig. 43 illustrates a modied form of mechanism for actuating the work indexing mechanism to cause the work to be indexed while remaining in position to be cut; Figs. 44, 45, and 46 are detailed views of elements comprising said modied form of indexing mechanism shown in Fig. 43; Fig. 47 is a cross sectional detail of a modified form of means for attaching interchangeable work engaging members to the indexing mechanism illustrated in cross section in Fig. 12; Figs. 48 and 49 are cross sectional details taken through the modified form of work engaging means shown in Fig. 47 and corresponding to the lines 48-48 and 49--49 respectively.

The illustrated embodiment of our invention comprises a broaching machine which has incorporated therein duplex features for greatly increasing the productive capacity of a pair of alternately reciprocal main slides, each of which may carry two broaching arbors or bars, and each bar has a set of finishing and a set of roughing cutters .thereon for cutting bevel gear teeth. We accordingly provide in the present embodiment of our invention two groups of work indexing and supporting mechanisms which present the gear blanks to, and support the blanks in a position to be cut by the four sets of roughing cutters and the four sets of finishing cutters. These mechanisms are of such character, as will be hereinafter apparent, that the work can be indexed on the completion of each single cycle of reciprocations of each slide and the tools carried thereby, and then upon the completion of a predetermined number of roughing and iinishing cuts and indexings of the work, the indexing mechanisms may be automatically swung away from the cutting paths of the tools thereby carrying the completed Work with them, and this same movement is eiective in causing a second anisms to present new work or uncut work set of Work supporting and work indexing mechl the path of movement of the cutting tools, these actions being brought about at predetermined periods in the reciprocating movements of the slides and the tools carried thereby.

In the drawings, We show in Fig. l a machine frame 60 designed to support a pair of reciprocating slides 6| in vertical position, these slides engaging upright slideways 62 rigidly supported by the machine frame in spaced apart relation whereby an actuating pinion 63 may engage racks 64 secured to the opposite side faces of the slides 6|, the pinion 63 being mounted upon a shaft not shown, and the shaft being driven through a suitable reduction gearing disposed within the portion 65 of the frame by a reversing motor 66. It will be understood, of course, that any suitable power reversing means may be utilized for driving the pinion 63 to alternately effect vertical reciprocation of the slides 6I.

Mounted upon the top of the machine frame are sprockets 68 over which extends a stretch of chain 69, the respective ends of which are attached to the top ends of the slides 6|, whereby the slide weights are counterbalanced. No further description or illustration of the slide design and actuation therefor is here given for a general mechanical arrangement for suitably mounting the slide to make it effective in supporting a broaching bar carrying two sets of cutting or broaching teeth is illustrated in the previously referred to Perkins, et al. Patent No. 1,486,604,

but the particular adaptation of the broaching bar illustrated in that patent to the present machine is modified to the extent that two broaching bars are mounted in cooperative pairs on each slide, and a precisioning means therefor is incorporated in the present invention as will be hereinafter described.

In Figs. 38 and 39 we show the general structure of the bars supporting the tools, and these bars comprise oscillatable members 10 of substantial weight and formedto receive and support a row of roughing cutters 12 and a row of finishing cutters 13 conforming in shape to a gear slot and angularly spaced apart 90. The cutters are mounted upon adjustable blocks 14 and 15 respectively, the blocks and cutters being maintained in position on the bars 10 by clamping members 18 which react against tapered sides formed on the cutters 12 and 13. Any suitable means, such as screw members 19, may engage the clamping strips 18 and the bodies of the bars 19 to clamp in adjusted position. In Fig. 18 a side elevation of part of one of the cutters 13 is illustrated, the roughing cutters and the finishing cutters being of substantially the same form.

The cuttercarrying bars 10 are mounted on the slides in such manner that upon the downward stroke of the slide on which they are mounted the two sets of roughing cutters act on two pieces of work positioned side by side, and upon the approach of the completion of the downward movement of the slide, the bars 'lil are oscillated through 90 to shift the roughing cutters out of the cutting path and thus bringing the finishing cutters into the cutting path before any substantial return or upward movement of the slide has taken place, and we show in Figs. 26 to 37 inclusive bar actuating means and precisioning means for bringing about this oscillating movement of the bars upon the completion of the roughing or downward movement of the cutters, and also upon the completion of the finishing or upward movement of the cutters. This mechanism may comprise as shown in cross section in Fig. 26 a pair of camming, indexing and precisioning plates t@ bolted together as shown at 8l, to comprise a unitary member insofar as functioning is concerned, and these members are accurately machined to slidably t upon reduced, upper extensions 'ma of the oscillatable broaching bars 10. The under faces of the members 89 are provided with camming surfaces @lla in the form of slots disposed 90 apart and indexing or precisioningr slots, coextensive with camming slots but having more acute surfaces llb. These two sets of slots coact with lugs on other members to be described to cause members 8l) to be elevated against the influence of spring members mounted to bear upon the members in pre-compressed condition by reason of retainer nuts ,96 threaded tothe uppermost ends of the extension lilla of the broaching bars 119. and also to cause members 80 to act as a precisioning means when the tools carried by the bars are cutting pieces of work. Hence the elevation or disengagement of the members 90 may be effectedby a pair of camming members 8S (see Figs. 26, 31, 32, and 33) coaxially mounted upon reduced portions 19e of the broaching bar lll. The members 925i are formed at the bottoms thereof to have meshing spur gear sectors tta, whereby they are caused to revolve in opposite directions when one of them is actuated, and as shown in Fig. 3l, one of the. members tu is provided with an extension 9B?) to support a stud 89, the stud carrying a roller @t in such position as to extend outwardly from a bearing block 9| which engages and supports the upper reduced portions 10c of the broaching bars. are thus disposed outwardly to engage cam members 92 and 93 (see Figs. 34 and 35) respectively disposed at upper and lower positions on the machine frame adjacent the path of movement of the slides to cause the members 88 to revolve in alternate directions upon each successive operation thereof by the respective cams. When the members 8B are thus revolved, the indexing plate comprising the members 80 is caused to be raised by reason of the action of four camming lugs 39e which normally rest in the slots defined by the surfaces 90a (see Figs. 27 and 28), the angles of these surfaces, however, being such that corresponding surfaces 83d formed on the lugs 88e (see Fig. 32) will cam the members 80 upwardly.

We provide a separate means in the mechanism shown in cross sectioninFig. 26 which will be acted upon by the members 88 to cause the broaching bars 1@ to be oscillated or indexed only after the members 80 have been cammed upwardly by the members 08 in the manner just described, and this means may comprise, as shown in Figs. 36 and 37, a pair. of members 95 disposed within the interiors of the members 88 but precisely secured to tapered portions 10d formed on the upper ends of the broaching bars 1li, and

The rollers 90 which are retained in place by nuts 9G in thread- Il ed engagement with the extensions 10a of the broaching bars. ri'hese members 95 are provided with radially extending lugs a, which are of less width than notches 88e (see Figs. 31 and 32) formed in the members 88, and in which the lugs 95a of the members 95 are disposed to swing. The members 95 are also provided with upwardly extending lugs 95h having surfaces complementary to the slots defined by the precisioning surfaces b formed in the under faces of the members 89. It will thus be seen that as the members 80 are revolved by reason of the stationary cams 92 and 93 upon the rollers 9D, no movement of the members 95 will be effect-ed and correspondingly no oscillating movement of the broaching bars 1li will be effected. until the members 88 have cammed the indexing members 83 upwardly, thus disengaging these members from the lugs 95h on the members 95. A continuation of the revolving movement of the members 88 will then cause the bars to be oscillated through 90 in opposite directions as indicated diagrammatically in Figs. 29 and 30. it may be added that the bars lll are suitably supported at their lower ends by bearing blocks attached to the lower ends of the slides and which may correspond to the bearing blocks 9i illustrated in Fig. 26. It will be noted that the bearing block 9i is of heavy design to absorb any longitudinal reactions transferred thereto by the bars lll during the heavy roughing out by the cutters on the work.

As previously stated we incorporate in the present machine duplex mechanism which may be alternately operated to present the work in pairs to the pairs of broaching bars as the latter are alternately reciprocated by the slides 5l, and each of these mechanisms may comprise two sets of work carrying and indexing' mechanisms with automatic means for shiftably supporting said mechanisms whereby one set may be active to support the work and index it, while the other set of indexing mechanisms is inactive and/or positioned so that the operator may remove the completed work and mount other uncut work upon the indexing mechanisms and the actuation of the various correlated mechanisms is effected by the reciprocating movements of the slides 6|. Accordingly, in Figs. 2 and 3, two groups of mechanisms are represented in right and lefthand mechanical arrangement and each group incorporates the use of four sets of work indexing mechanisms. We will rst describe the manner of mounting the indexing mechanisms'on a revolving means for supporting them and will refer particularly to Figs. 2 to 9 inclusive and Fig.

11 of the drawings.

In Fig. l1, one pair of work indexing units is shown as detached from the machine and with a work blank (a bevel gear blank) mounted thereon. In Figs. 2 and 3, are shown in front elevation, triangularly shaped frame members |00 and |0|, which, as shown in cross section in Fig. 9, revolubly support a frame member |02 made in the form of a hollow casting with pedestal pads or blocks |03 preferably integrally formed thereon, and upon which may be mounted casings |06 comprising the frames of the indexing mechanisms. This, casing |06, as shown in 'cross section in Fig. 12, is of such form as to support two work indexing mechanisms and the triangularly shaped frame members |00 and |0| are pivotally mounted upon a rod or bar |04 supported by bearing brackets |05 resting on an adjustable slide frame carried by a front projecting portion of the machine frame 60, whereby the two frame members |00 and |0| may be oscillated in unison through linkage mechanism actuated by the slides 6I as the latter reciprocate.

This linkage mechanism also includes the means for predetermining the number of broaching strokes upon the Work before the work is withdrawn from thepath of movement of the broaches and is arranged in duplicate at the two sides of the machine frame, but only one group of such members as comprise this mechanism will be described. The frame members 00 and |0| accordingly have the outer or lower front triangular ends thereof secured to cross member |06 and pivotally connected to the cross bar |08, are links |09, the lower ends of the links |09 being pivotally connected to bifurcated links and |||a mounted upon a rocking shaft ||2 suitably supported to extend through the frame member ||0. The frame member 0 is adjustably mounted on the bed of the machine ||0a by means of the tongue and groove ||0b and adjustment screws ||0a, whereby the work may be moved relative to the cutters and a fine adjustment is obtained. It will be noted that the links |09 and constitute a toggle for swinging the triangularly shaped frame members |00 and 0| supported thereby about the axis of the rod |04, and this oscillating movement ise'ected only upon a predetermined number of reciprocations of the slide and the means for actuating this toggle mechanism at certain predetermined times will now be described.

Disposed at one side of the frame member ||0 is a member I l5 reciprocally supported by links or arms I6 and ||'l, the member ||5 being reciprocated back and forth each time the broach carrying slide 6| makes one cycle of reciprocatlons. In other words, the link 6 is actuated by reason of the cam ||6a mounted on the slide to engage a roller carried by the lever arm ||8 and which is rigidly mounted on a stud shaft ||9 to which the link ||6 is secured, the stud shaft being supported in juxtaposition to the reciprocating movement of the slide and the cam carried thereby, by bracket member |20. It will be noted that the link ||1 is pivotally mounted on the bar |04 YYbut is not directly effective in causing any movement of the frame members |00 and |0| mounted on the bar |04. 5 Associated with the reciprocating member l5 is a counting mechanism which functions in such manner that levers |36 and |48 indirectly transmit motion to the frame members 00 and 10|, after a predetermined number of working cycles 10 of the cutting tool or broach. The links |09, and |||a are thus caused to be aligned or to hinge toward each other and bring about the upward or downward swinging of the frame members |00 and |0| about the rod |04. As 15 shown in Figs. 5, 6, and 7, the counting mechanism may comprise means controlling the positioning of the lever |36 whereby the latter becomes effective to cause the fixture to be swung from the position shown in Fig. 4 to the position shown in Fig. 6. This means includes an arm |20 oscillatably supported by a stud I 2| secured to a bracket member |22a attached to the side wall of the frame member I0. On the arm |20 is a downwardly extending portion |2 la upon which 25 is mounted a pawl |22, the latter being resiliently urged in contact with a ratchet Wheel |24 also mounted on the stud |2|, a spring |25 serving to act on the pawl. The ratchet wheel |24, as shown in Fig. 7, is mounted upon the 30 stud |2| to be readily replaceable by other ratchets having a different number of teeth thereon for a reason which will hereinafter become apparent. The number of reciprocatlons which the main slide may make while the work is being 35 maintained in position to be cut by the cutters mounted thereon is determined by the number of teeth in the ratchet, and accordingly the ratchet wheel is keyed to a disc |30, which acts on lever |36 through cam |35 rigidly mounted o thereon. This disc member also serves as a friction brake by reason of the spring urged plunger |3| acting thereon to prevent any overtravel thereof, the plunger |3| being suitably supported by a bracket |32 attached to the frame member 45 ||0. It will thus be seen that each time the reciprocating member I5 makes one cycle of movements the ratchet and consequently the disc |30 is advanced through an angle corresponding to the angular span of one tooth in the ratchet, 50 and when the disc is revolved to bring the cam member |35 to the position shown in Fig. 6, the

cam will cause the lever |36 to be interpositioned in the oscillating path of the extension ||1a of the link ||1 to transmit motion from the lever 55 |36 to the toggle linkage hereinbefore described. The lever |36 is mounted on a slidable bar |31, one end of which is slidably supported by a bracket |38 attached to the machine frame, while the other end is pivotally connected as indicated at 60 |39 (see Figs. 5 and 6) to the toggle link member Thus at a predetermined time or after a predetermined number of reciprocatlons of the main slides 6|, the link ||1 becomes effective to cause the toggle levers |09, and |||a to be drawn 65 from the extended position shown in Figs. 4 and 5 to a collapsed position as shown in Fig. 6, thus causing the frame members |00 and |0| to swing downwardly around the axis of the rod |04, and consequently causing the indexing mechanisms carried by the frame member |02 to be swung away from the reciprocating path of movement of the broaching tools on the main slide 6|, without arresting the continuous reciprocating movements of the main slide.

aozmoiv and 7), which has formed thereon a small camA .|4|, in such position as to pass between the pawl |22 and the ratchet teeth and thus raise the pawl out of engagement with the ratchet teeth as the frame members and |0| are caused to be lowered as shown in Fig. 6. This we accomplish through a connecting rod |44 attached at one of its ends to the lever` |40, and at the other end to an extension Illb formed on the top of the lever It will thus be seen that the entire work supporting means will remain in the retracted position shown in Fig. 6 as long as desired, while the main slide continues to reciprocate.

To cause the xture to be elevated to the position shown in Figs. 4 and 5, we arrange the dog ,lever |48 in pivotal attachment to the bar |31 whereby it may be elevated to have the end thereof become interpositioned in the path of movement of the end ||'|a of the link As will be obvious, the link is agitated or oscillated as long as the main slides of the machine are in operation. This dog lever |48 may be brought to operative position in any suitable manual manner, but we prefer to provide a means for raising the lever |40 whereby the latter can be set to be snapped into operative position rgardless of the oscillating position of the end Illa of the lever IH. A device for accomplishing this may comprise a manually operated-lever |50 (see Figs. 6 and 8) supported by a bracket attached to a side wall of the frame member lll) in such position that a spring urged plunger member |52, carried by the hub portion of the lever |50, will engage the underside of the lever |40 when the lever |50 is shifted from the position shown in Fig. 6 toward the left and as the end lila of the link is oscillated to the extreme right, the plunger |52 will cause the lever,

rf'gm right to left, thus causing the toggle links to be shifted to lie in an upright position and consequently cause the indexing mechanisms and the work carried thereby to be swung to the path of movement of the cutting tools on the reciprocating slides. It will be noted that the foregoing described mechanisms for actuating the work carrying fixtures comprise members, some of which are constantly operated so long as the main slides are in operation while other of the members are acted uponby a timing mechanism which determines the period, measured in reciprocation cycles of the main slides, that the fixture is permitted to remain in elevated position with the Work mounted interposed in the path of movement of the cutting tools carried by the slides, and we provide precisioning means which will assure accurate presentation of the work to such position, which will be hereinafter described.-

Having described the means by which the Work supporting and indexing mechanisms hereinbefore generally referred to are caused to be presented to the path of movement of the reciprocating cutters, we will now describe the manner by which these indexing mechanisms are swung on the fixtures and will thereafter describe the manner in which the indexingmechanisms index the work with precision, while the work is maintained in the path of movement of the cutters. In Figs. 4, 6, 9, and l0, disc members |60 are shown as being rigidly mounted upon the revolving frame member |02, and upon which the indexing mechanisms are supported and the discs |60 have mounted thereon, inpositions 180 apart, precisioning blocks or wedges |6| of such shape and disposed in such position that when the frame members |00 and |0| are swung about the bar |04, they will engage precisioning blocks |63 rigidly but adjustably supported by a thrust frame member |64 mounted on the machine frame at each side of each main slide. In other words, there are two frame members |64, two discs |60 and corresponding coacting precisioning Wedges for each set of fixtures. The discs |60 also carry, at positions 180 apart thereon, precisioning sleeves |68 (see Figs. 4, 9, and 10) which are engaged by spring urged plungers |60, the latter being supported in a suitable bore formed in the triangularly-shaped frame members |00, and these plungers |69 are manually operated by a lever` lwhen it is desired to manually revolve the disc members |60, and consequently the two pairs of indexing mechanisms carried thereby. The handle of the lever |10, as will be noted in Fig. 10, is provided with a lug |1| which will prevent any operation of the manual lever |50 when the plunger |69 is manually withdrawn from locking relation with Athe discs If desired, the discs |60 may be revolved automatically instead of manually at predetermined periods relative to the reciprocating movements of the main slides 6|, and we show in Figs. 40, 41, and 42 a modified arrangement whereby this may be accomplished. Such mechanism may comprise a friction drive acting on a disc |90 having a beveled circumferential surface for friction drive and this friction drive being effected by a cone member |80, the cone being driven by a. belt IBI, and the belt being driven by a source of power application not shown. The cone |00 is mounted upon a sleeve |82 suitably supported by a bracket |83, the bracket |03 being mounted rigidly upon the frame member ||0 in such position that as the frame members |00,

`and |0| cause the indexing mechanisms to-be beveled perimeter of the disc |00 will come into driven contact with the driving cone |80 and thus cause th'e member |02 and indexing mechanisms carried thereby to be revolved.

The frame members |a of the indexing mechanism shown in the modification (Figs. 41, 42, and 43) are normally prevented from rotating relative to the carriage frame members |00 and |0|, by suitable plungers |6511, one of which is shown in Fig. 41. The plunger shown is carried by the frame member |00, and the other, which is not shown, is carried in the same manner by the frame member |0|. The plunger 69a engages a recess. |68 in the indexing member |60 in much the same manner as did the plunger |60, heretofore described. In this modification, however, each plunger |68a is normally retained in engagement with its respective recess by a frame member |00 is rocked in a clockwise direction about its pivot |04, the bevelled nose of the plunger willl engage a stationary bevelled lug lmember |00, and is positioned so that as the or cam member I9I, which is rigidly secured to the stationary frame bracket |83. Accordingly, as the frame member |00 is rocked in a clockwise direction to move the work holding and indexing mechanism out of the path of the broach, the bevelled surface |69c of the movable plunger |09a is lowered into engagement with the stationary cam member |9I. The continued clockwise movement of the frame member |00 causes the plunger |69a to be cammed outwardly by the stationary member |9|, thereby causing the parts to be moved to the position shown in Fig. 4l, in which position the plunger |89a is withdrawn from its coacting recess |88.

Immediately before the locking plunger |69a is disengaged from the recess |68, a friction driving disk |80 is engaged by a disk |90, which is secured to the shaft I 02 of the carriage. Hence, as soon as the plunger |69a disengages its recess |68, the work holder and indexing mechanism will be automatically rotated by such friction drive.

In addition to automatically initiating the rotation of the index and workholding mechau nisms, the mechanism is so arranged that it will be automatically stopped and locked in position. Likewise,.the control lever |50 will be automatically reset to cause the frame members |00 and I0! to be rocked in a counter-clockwise direction around their pivots, returning the work to a broaching position, as heretofore described.

To accomplish this, the rotation of the disk |60a is interrupted. As shown in Figs. 41 to 43, a cam disc |94 is secured to the disc |60a and its periphery is engaged by a roller |96, carried by a lever |91, pivotally mounted on the sleeve |82. 'I'he lever |91 is connected by a spring connection |9'Ib to a second lever |91a, which is rigidly secured to the sleeve. Another lever |98 is rigidly secured to the sleeve |82, and is normally drawn in a clockwise direction by a suitable spring I98a, one end of which is secured to the lever |98 and the other end to the machine frame 0. 'This arrangement is such that the springs |98a and |911; serve to maintainvthe roller |98 in contact with the periphery of the cam disc |94.

In the embodiment shown, there are two workholders and indexing mechanisms, K and L, which are diametricallv opposed to each other, as shown in Fig. 4. 'I'he same is true of the modification shown in 41 to 43, inclusive. The machine is so arranged that the disc |60a will be stopped and locked in position after it has turned through/half a revolution. To accomplish this the cam disc |94 is provided with two projecting peripheral surfaces |94a, spaced diametrically from each other, and arranged to act on the roller |96 to cause the levers |91, |91a and |98toberockedasaunlt. Thespringconnection between the levers |91 and |91a is considerably stronger than the spring |98a which acts to retain the levers in their clockwise positions, hence, as the lever |98 is rocked, it moves the lever |98, which in turn, moves the lever |50 from the position shown in Fig. 4, to the position shown in Fig. 40. A link 250 is connected at one end to the lowermost end of the lever |98 and is provided with a pin and slot connection, 25|-252, with the lever |50, below its pivot 253. Therefore, as the lever |98 is rocked in a counter-clockwise direction, the far end of the slot 252 will engage the pin 25|, thereby moving the lever |50 to the position shown in Fig. 40. This movement ot the lever |59 raises the dos lever |48 from the position shown in Fig. 5 to the position shown in Fig. 6, in which'position it will be engaged by the lever |'I0a ony the next rearward stroke. As the dog lever |48 is moved to the right, Fig. 5, it straightens the toggle |09, 5 III, rocking the frame members 00 and |0| to the broaching position shown in Fig. 4, and at the same time an ear 255 on the lower side of the dog lever |48 engages a plunger |52 (Fig. 5), heretofore described, returning the lever |50 to its normal position, as shown in Fig. 4, with the pin 25| (Fig. 40) riding idly in the slot 252.

As soon as the frame members |00 and |0| start to rock about their pivots, due to the action of a cam |94a, and the linkage |98, |91, |98, 15 and |48, as heretofore described, the plunger |69a, which is carried by the carriage, begins to move away from the stationary member |9|, and is shoved by a spring |691; toward the face of the disc |09.y As the disc is rotated by the friction drive, heretofore described, the plunger |69a will seat in a recess |68, stopping the rotation of the disc |60a and locking it in position relative to the frame members |00 and |0|.

The friction drive is arranged through the medium of a spring |82a which urges the driving member |80 toward the driving disc |98 to maintain contact between the disc and the driving member |80, until after the plunger |69a is seated. It will be apparent that While we have described one means of automatically shifting the work to and from the path of the cutting tools after the completion of a predetermined number of cutting strokes of the reciprocating broaches, other means may be utilized for eifect- 35 ing the same, which we would consider to lie within the scope of our invention.

We will now describe the work indexing mechanisms and their mode of operation. As shown by the dot and dash lines in Fig. 4, one pair of 40 working indexing mechanisms K are in operative position with the two pieces of work W carried thereby disposed to lie in the cutting path of the reciprocating tools carried by the slid'e on the main frame of the machine. A second 45 pair of indexing mechanisms is shown in the same figure at L, and it will be noted frm this figure that the ends of the fixtures to which the work W is attached, are disposed at an outward upwardly facing position whereby the operator may 50 readily attach the work to the indexing mechanisms as the machine operates upon the work W carried by the indexing mechanisms K.

It will be noted in Fig. 4 that the indexing mechanisms K and L are mounted upon the revolving frame member |02 in such manner that when the indexing mechanisms are swung to bring the work W into the cutting path of the broaching tools, that the angular relation between the axes of the indenng mechanisms and incidentally the gear blanks carried thereby and coaxially mounted thereon arebrought into the desired exact angular relation to lthe vertical, whereby the broaching tools will accurately cut beveled gear teeth without necessitating any further nishing of the gear teeth, and when 1t is desired to cut beveled gears, the teeth of which have pitch angles different than the work blanks herein illustrated, the indexing mechanisms are .mounted on the revolving frame at the desired angle relative to the vertical.

As stated in the present instance, the work W (see also Figs.1 11 and l2) comprises beveled gear blanks having a threaded bore, and accordinglytheindexing areprovided with 'le 

